1. Field of Invention
This invention relates in general to offshore drilling and production equipment and in particular to a tieback connector assembly for connecting a subsea wellhead assembly to a platform.
2. Description of Related Art
A subsea wellhead assembly installed at the sea floor may be in water thousands of feet deep. During completion and certain production operations, components from a floating platform are lowered from the platform to engage the subsea wellhead assembly. A tieback connector connects a production riser between a subsea wellhead housing and the surface production platform. Typically, the tieback connector has locking elements that lock into a profile in the wellhead housing. A lockdown mechanism is sometimes used to resist upward movement of the tieback connector and prevent unintentional unlocking of the tieback connector that may occur due to thermal growth and external environmental forces during production.
Some current lockdown mechanism designs include multiple lockdown members that are spaced around the circumference of the lockdown mechanism. Installing the lockdown mechanism usually requires a remotely operated vehicle (ROV) that manually manipulates a plate of each lockdown member with a grooved profile into engagement with a rod with a mating profile. In some subsea developments, the wells are located on a template, which provide limited access for a ROV, and it is very difficult for the ROV to move around and between the wells to make up the various lockdown members.